The present inventors previously developed atmospheric plasma generators and filed patent applications therefor (see Patent Documents 1 and 2). In the plasma generators, electrode surfaces facing each other are provided with micro-scale recesses, to thereby induce hollow cathode electric discharge, through which a plasma is generated. When a plasma-generating gas is caused to pass through the plasma-generating zone, a gas containing at least a plasma can be jetted. Through employment of such a plasma generator, high-density plasma can be readily generated under atmospheric pressure with high-frequency voltage of about some kilovolts obtained from a single-phase commercial power source (100 V) by means of a voltage booster.
Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. 2006-196210
Patent Document 2: Japanese Patent Application Laid-Open (kokai) No. 2006-272039